【摘要】 大功率垂直腔面发射激光器(VCSEL)在激光泵浦、激光测距、激光雷达等领域有广泛的应用前景,但目前的常规激光器材料结构尚未针对大功率激光输出进行优化设计。特别是为获得大功率激光输出所采用的大出光窗口导致的激光光束质量劣化成为限制其应用发展的核心问题之一。针对上述问题对激光器材料结构与器件结构进行了两方面的新结构设计和研制:(1)以实现大功率激光输出为目标,材料结构设计上对出光窗口一侧的N-DBR反射率进行了调整,以具有99.3%反射率的n-DBR替代常规结构中所采用的99.7%以上反射率。与常规材料结构相比,采用优化后的材料结构制备的直径500μm出光孔径的单管器件在注入电流110 A时激光输出功率达到102 W,而单元出光窗口直径100μm的5×5阵列在100 A电流下的激光输出功率为103 W,单元直径为140μm的8×8阵列在130 A注入电流下的激光输出功率达到115 W;(2)针对大出光窗口导致的光束质量劣化,通过湿法化学刻蚀研制了直接集成在出光窗口表面的微透镜结构,单元出光窗口直径为90μm的6×6阵列器件在4 A注入电流下的激光光束发散角压缩到6.6°,与未集成微透镜时的14.8°相比有了大幅改善。实验结果表明:降低n-DBR反射率及集成微透镜结构有效地改善提高了大功率垂直腔面发射激光的输出功率和激光光束质量。更多还原

【Abstract】 High-power vertical-cavity surface-emitting lasers(VCSEL) can be used as the laser source of laser pumping,laser ranging,and LIDAR,etc.The material structure of VCSEL was rarely optimized directly for high power operation.The deterioration of beam quality of VCSEL caused by large emitting window for high power operation is becoming a key problem for the application of high power VCSEL.Two novel techniques were proposed to improve the performance of VCSEL.The reflectivity of n-DBR was slightly decreased to 99.3% instead of 99.7% as commonly used in conventional VCSEL.A record power of 102 W was realized at a current of 110 A for a 500 μm-aperture VCSEL.Output powers of 103 W and 115 W were respectively demonstrated for a 5×5 2D array with the single emitter of 100 μm-aperture and a 8×8 2D array with the single emitter of 140 μm-aperture.For the deterioration of beam quality,microlens were directly integrated onto the emitting window by wet etching the GaAs subatrate.The divergent angle of a 6×6 2D array with the single emitter of 90 μm-aperture was suppressed to 6.6°,indicating a strong improvement compared with the divergent angle of 14.8° for an array without microlens.The results above shows that the performance of high power VCSEL is greatly improved by the optimization of n-DBR reflectivity and the integration of microlens.更多还原